Superluminal Neutrinos: Experimental Data and New Interpretative Theories

We calculate the quasiclassical probability to emerge the quantum fluctuation which gives rise to the quark-matter drop with interface propagating as the self-similar spherical detonation wave (DN) in the ambient nuclear matter. For this purpose, we make use of instanton method which is known in the quantum field theory.

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Accelerated frames and galactic rotation curves

Modern Physics Letters A ◽

10.1142/s0217732319502183 ◽

2019 ◽

Vol 34 (27) ◽

pp. 1950218

Author(s):

S. C. Ulhoa ◽

F. L. Carneiro

Keyword(s):

Experimental Data ◽

General Relativity ◽

Dark Matter ◽

Reference Frame ◽

Rotation Curve ◽

Reference Frames ◽

Galactic Rotation ◽

Inertial Reference Frame ◽

Galactic Rotation Curve ◽

Accelerated Frames

In this paper, the galactic rotation curve is analyzed as an effect of an accelerated reference frame. Such a rotation curve was the first evidence for the so-called dark matter. We show another possibility for this experimental data: non-inertial reference frame can fit the experimental curve. We also show that general relativity is not enough to completely explain that which encouraged alternatives paths such as the MOND approach. The accelerated reference frames hypothesis is well-suited to deal with the rotation curve of galaxies and perhaps has some role to play concerning other evidences for dark matter.

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Fermionic Casimir effect in Horava–Lifshitz theories

International Journal of Modern Physics A ◽

10.1142/s0217751x19501070 ◽

2019 ◽

Vol 34 (20) ◽

pp. 1950107

Author(s):

Dêivid R. da Silva ◽

M. B. Cruz ◽

E. R. Bezerra de Mello

Keyword(s):

Boundary Condition ◽

Casimir Effect ◽

Lorentz Symmetry ◽

Casimir Energy ◽

Quantum Field ◽

Parallel Plates ◽

Symmetry Violation ◽

Massless Quantum

In this paper, we analyze the fermionic Casimir effects associated with a massless quantum field in the context of Lorentz symmetry violation approach based on Horava–Lifshitz methodology. In order to obtain these observables, we impose the standard MIT bag boundary condition on the fields on two large and parallel plates. Our main objectives are to investigate how the Casimir energy and pressure depend on the parameter associated with the breaking of Lorentz symmetry.

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Lorentz symmetry violation, dark matter and dark energy

10.1063/1.3462620 ◽

2010 ◽

Cited By ~ 9

Author(s):

Luis Gonzalez-Mestres ◽

Jean-Michel Alimi ◽

André Fuözfa

Keyword(s):

Dark Matter ◽

Dark Energy ◽

Lorentz Symmetry ◽

Symmetry Violation

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Theoretical views on Szilard Chalmers reactions in solid systems. II. Parent reformation by billiard-ball collisions

Canadian Journal of Chemistry ◽

10.1139/v68-531 ◽

1968 ◽

Vol 46 (20) ◽

pp. 3201-3209 ◽

Cited By ~ 2

Author(s):

W. H. Wong ◽

D. R. Wiles

Keyword(s):

Experimental Data ◽

Thermal Decomposition ◽

Initial Energy ◽

Projectile Energy ◽

Metal Carbonyls ◽

Present Stage ◽

Complex Ions ◽

Billiard Ball ◽

Lower Limits ◽

Mathematical Operations

The problem of billiard-ball replacement reactions of atoms centrally located in the molecule has been approached, using the approximation of simple two-body collisions. The reentry process has been separated into steps which can be handled by straightforward mathematical operations. Collision diameters for given energy transfer were calculated using an exponentially screened potential.Species treated include dicyclopentadienyl metals, arene metal carbonyls, and hexacoordinated complex ions, although the method is applicable to many other types of compound. An important result is that the probability of successful billiard-ball replacement is not sensitive to the initial energy, as long as this is not too low. It is concluded that this method is, at its present stage, most useful in calculating lower limits for billiard-ball reformation by following the projectile energy down to ca. 100 eV. Below this energy it is considered that thermal decomposition of the reformed molecule is likely. Results of the calculation are compared with experimental data, and further experiments are suggested by which the contribution of billiard-ball collisions may be directly assessed.

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Electronic Conduction in Disordered Carbon Materials

10.26686/wgtn.17009675.v1 ◽

2021 ◽

Author(s):

◽

Chun Yee Cheah

Keyword(s):

Experimental Data ◽

Data Analysis ◽

Electronic Transport ◽

Carbon Materials ◽

Electronic Conduction ◽

Transport Mechanisms ◽

Temperature Dependent ◽

Quantum Tunnelling ◽

Field Dependent ◽

Disordered Carbon

Graphene, consisting of a single layer of carbon atoms, is being widely studied for its interesting fundamental physics and potential applications. The presence and extent of disorder play important roles in determining the electronic conduction mechanism of a conducting material. This thesis presents work on data analysis and modelling of electronic transport mechanisms in disordered carbon materials such as graphene. Based on experimental data of conductance of partially disordered graphene as measured by Gómez-Navarro et al., we propose a model of variable-range hopping (VRH) – defined as quantum tunnelling of charge carriers between localized states – consisting of a crossover from the two-dimensional (2D) electric field-assisted, temperature-driven (Pollak-Riess) VRH to 2D electric field-driven (Skhlovskii) VRH. The novelty of our model is that the temperature-dependent and field-dependent regimes of VRH are unified by a smooth crossover where the slopes of the curves equal at a given temperature. We then derive an analytical expression which allows exact numerical calculation of the crossover fields or voltages. We further extend our crossover model to apply to disordered carbon materials of dimensionalities other than two, namely to the 3D self-assembled carbon networks by Govor et al. and quasi-1D highly-doped conducting polymers by Wang et al. Thus we illustrate the wide applicability of our crossover model to disordered carbon materials of various dimensionalities. We further predict, in analogy to the work of Pollak and Riess, a temperature-assisted, field-driven VRH which aims to extend the field-driven expression of Shklovskii to cases wherein the temperatures are increased. We discover that such an expression gives a good fit to the data until certain limits wherein the temperatures are too high or the applied field too low. In such cases the electronic transport mechanism crosses over to Mott VRH, as expected and analogous to our crossover model described in the previous paragraph. The second part of this thesis details a systematic data analysis and modelling of experimental data of conductance of single-wall carbon nanotube (SWNT) networks prepared by several different chemical-vapour deposition (CVD) methods by Ansaldo et al. and Lima et al. Based on our analysis, we identify and categorize the SWNT networks based on their electronic conduction mechanisms, using various theoretical models which are temperature-dependent and field-dependent. The electronic transport mechanisms of the SWNT networks can be classed into either VRH in one- and two-dimensions or fluctuation-assisted tunnelling (FAT, i.e. interrupted metallic conduction), some with additional resistance from scattering by lattice vibrations. Most notably, for a selected network, we find further evidence for our novel VRH crossover model previously described. We further correlate the electronic transport mechanisms with the morphology of each network based on scanning electron microscopy (SEM) images. We find that SWNT networks which consist of very dense tubes show conduction behaviour consistent with the FAT model, in that they retain a finite and significant fraction of room-temperature conductance as temperatures tend toward absolute zero. On the other hand, SWNT networks which are relatively sparser show conduction behaviour consistent with the VRH model, in that conductance tends to zero as temperatures tend toward absolute zero. We complete our analysis by estimating the average hopping distance for SWNT networks exhibiting VRH conduction, and estimate an indication of the strength of barrier energies and quantum tunnelling for SWNT networks exhibiting FAT conduction.

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Electronic Conduction in Disordered Carbon Materials

10.26686/wgtn.17009675 ◽

2021 ◽

Author(s):

◽

Chun Yee Cheah

Keyword(s):

Experimental Data ◽

Data Analysis ◽

Electronic Transport ◽

Carbon Materials ◽

Electronic Conduction ◽

Transport Mechanisms ◽

Temperature Dependent ◽

Quantum Tunnelling ◽

Field Dependent ◽

Disordered Carbon

Graphene, consisting of a single layer of carbon atoms, is being widely studied for its interesting fundamental physics and potential applications. The presence and extent of disorder play important roles in determining the electronic conduction mechanism of a conducting material. This thesis presents work on data analysis and modelling of electronic transport mechanisms in disordered carbon materials such as graphene. Based on experimental data of conductance of partially disordered graphene as measured by Gómez-Navarro et al., we propose a model of variable-range hopping (VRH) – defined as quantum tunnelling of charge carriers between localized states – consisting of a crossover from the two-dimensional (2D) electric field-assisted, temperature-driven (Pollak-Riess) VRH to 2D electric field-driven (Skhlovskii) VRH. The novelty of our model is that the temperature-dependent and field-dependent regimes of VRH are unified by a smooth crossover where the slopes of the curves equal at a given temperature. We then derive an analytical expression which allows exact numerical calculation of the crossover fields or voltages. We further extend our crossover model to apply to disordered carbon materials of dimensionalities other than two, namely to the 3D self-assembled carbon networks by Govor et al. and quasi-1D highly-doped conducting polymers by Wang et al. Thus we illustrate the wide applicability of our crossover model to disordered carbon materials of various dimensionalities. We further predict, in analogy to the work of Pollak and Riess, a temperature-assisted, field-driven VRH which aims to extend the field-driven expression of Shklovskii to cases wherein the temperatures are increased. We discover that such an expression gives a good fit to the data until certain limits wherein the temperatures are too high or the applied field too low. In such cases the electronic transport mechanism crosses over to Mott VRH, as expected and analogous to our crossover model described in the previous paragraph. The second part of this thesis details a systematic data analysis and modelling of experimental data of conductance of single-wall carbon nanotube (SWNT) networks prepared by several different chemical-vapour deposition (CVD) methods by Ansaldo et al. and Lima et al. Based on our analysis, we identify and categorize the SWNT networks based on their electronic conduction mechanisms, using various theoretical models which are temperature-dependent and field-dependent. The electronic transport mechanisms of the SWNT networks can be classed into either VRH in one- and two-dimensions or fluctuation-assisted tunnelling (FAT, i.e. interrupted metallic conduction), some with additional resistance from scattering by lattice vibrations. Most notably, for a selected network, we find further evidence for our novel VRH crossover model previously described. We further correlate the electronic transport mechanisms with the morphology of each network based on scanning electron microscopy (SEM) images. We find that SWNT networks which consist of very dense tubes show conduction behaviour consistent with the FAT model, in that they retain a finite and significant fraction of room-temperature conductance as temperatures tend toward absolute zero. On the other hand, SWNT networks which are relatively sparser show conduction behaviour consistent with the VRH model, in that conductance tends to zero as temperatures tend toward absolute zero. We complete our analysis by estimating the average hopping distance for SWNT networks exhibiting VRH conduction, and estimate an indication of the strength of barrier energies and quantum tunnelling for SWNT networks exhibiting FAT conduction.

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Limiting Velocities of Primary, Obscure and Normal Particles: Self-Annihilating Obscure Particle as an Example of Dark Matter Particle

Applied Physics Research ◽

10.5539/apr.v8n5p1 ◽

2016 ◽

Vol 8 (5) ◽

pp. 1

Author(s):

Josip Soln

Keyword(s):

Dark Matter ◽

Mass Velocity ◽

Crab Nebula ◽

Dark Matter Particle ◽

Muon Neutrino ◽

Annihilation Process ◽

Small Energy ◽

Maximum Value ◽

Particle Parameter ◽

Normal Particle

From recently established bicubic equation, three particle limiting velocities are derived, primary, c1,obscure, c2 and normal, c3,that in principle may belong to a single particle. The values of limiting velocities are governed by the congruent particle parameter, z = 3\sqrt3mv2=2E, with m; v and E being, respectively, particle mass, velocity and energy, generally satisfying 1 <= z <= 1, and here just 0 <= z <= 1. While c3 is practically the same in value as v, c1 and c2 can depart from v as z changes from 1 to 0, since c1, c2 and c3; are, in forms, explicitly different from each other, which offers the chance to look at possible new forms of matter, such as dark matter. For instance, one finds that c3 could be slightly different from c, the velocity of light, for the 2010 Crab Nebula Flare PeV electron energy region and for the OPERA 17 GeV muon neutrino velocity experiments, while at the same time, although not measurable in these experiments, calculated c1 and jc2j, are numerically about 105 times larger than c3. There is a belief that an exemplary particle of small velocity, v = 10-3c ,and small energy, E = 1eV , but as yet of not known mass, should belong to the dark matter class. Once knowing z the value of the mass is fixed with 3\sqrt3m(z)v2 = 2Ez ,and its maximum value m(1) is at z = 1, m(1) = 2E=(v23\sqrt3):This mass value defines the test particle, with which one calulates primary, obscure and normal particle rest energies at z = 1: Snce at z = 1 theory predicts c21(1) = (3=2) v2;c22 (1) = 3v2; c23 (1) = (3=2) v2, the rest energies are m(1) c21(1) = m(1) c23(1) = 0:58eV and m(1)(c22(1))= 1:15eV. The primary and normal particles, with positive kinetic energies self-creation process increase their energies from 0:58eV to desired1eV: The obscure particle, with negative kinetic energy self-annihilation process decreases its energy of 1:15eV to desired 1eV. This makes the obscure (imaginary c2) particle as a good candidate for a dark matter particle,since as it is believed that a trapped dark matter particle with self-annihilation properties helps keeping the equilibrium between capture and annihilation rates in the sun.

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